Furnace arch



J W. GATES.

FURNACE ARCH.

APPLICATION FILED DEC.6, 1919.

1 $104,845 Patented Jan. 31, 1922.

irao STATES PATENT ores.

JOHN W. GATES, 0F MONTREAL, QUEBEC, CANADA.

FURNACE ARCH.

ToaZZ whom it may concern:

Be it known that I, JOHN W. GATES, a subject of the King of Great Britain, and resident of the city of Montreal, in the Province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Furnace Arches, of which the following is a full, clear, and exact description.

This invention relates to-improvements in furnace arches and is applicable equally to all types of arches such as Dutch ovens, stoker arches, combustion arches in oil and gas burning furnaces, baflies, and various types of metallurgical-and other furnaces.

The object of the invention is to provide an archin which the blocks are supported in such a manner that they may be very readily removed in one locality without disturbing the remainder of the arch.

A further object is to provide an arch which will be securely supported by means which will not sag and which will not be subject toany considerable movement due to ex ansion or contraction.

he arch according to this invention comprises a grid of tubular members, through which a coolin medium may be circulated and a series 0 blocks notched in their up per portions for support from the grid and to receive means for attaching them to the rid. b In the drawings which illustrate the invention:-

Fig. 1 is a cross section of one form of furnace arch.

Fi 2 is a longitudinal section correspon ingto Figure 1.

* porting grid.

Fig. 3 1s apartial plan view of the'sup- Fig. 4 is a fragmentary sectional view illustrating a slight modification.

Referring more particularly to the drawings, 11 designates the side walls of a furnace shouldered at 12 to support the ends of an arch 13 forming the top of the furnace.

Broadly speaking, the arch is composed ofv blocks of any suitable form' suspended by any suitable means from a grid 14 composed of tubular longitudinal members 15 and tubular transverse members 16 connected by any suitable means .17 at their points of intersection. The blocks of the arch are supported, for-example, by the longitudinal members 15 which are located below the transverse memberslfi. In such an arrange- Specification of Letters Patent. Patent d J 31 1922 Application filed December 6; 1919.

Serial No. 342,877.

ment, the inlets 18 for the cooling agent are provided in the longitudinal members and the outlets 19 in the transverse members, these inlets and outlets being in any suitable arrangement and of any suitable size, according to the nature of the furnace and the manner of disposal of the cooling agent. Water obviously is the most suitable a ent for the purpose and, in constructions w ere the hot water produced is of no use, it ma be discharged to a sewer. Then the are forms part of a boiler furnace, the supporting grid may serve as a feed water heater or may be arranged as a leg from the boiler. Obviously, the {blocks may be suspended from the transverse members of the grid and the longitudinal members disposed above the transverse members, so as to support the same. The upper layer of tubular members which in the form illustrated are the transverse members 16, rest at their ends upon the top of the furnace w'alls,.so that the grid and the arch suspended therefrom are supported by the furnace walls.

The arch blocks may be supported from the grid ina number of ways, of which only two are illustrated. In Figure 1, the arc '20 and 21, so that they are held against falling into the furnace. The blocks 20 and 21 project above the blocks 22, so that recesses or grooves 23 are provided in the top of the arch in which the grid members 15 are received. The portions of the blocks forming the side walls of these grooves 23 may be undercut in any suitable manner to produce grooves, which are narrower at the top than at a lower level. Preferably the width of the grooves 23 at their tops ls'just sufficient for the entrance of the grid members 15,but at a point below the. top, there is considerable clearance between the sides of the grooves and the grid members. These spaces are occupied by wedges or fillers 24.- which bear against the blocks and grid mem- 21 and between i rovided. These blocks taper down-p sides are supits bers and hold the blocks to the grid. For convenience, and security of support, the grid members may be elliptical in cross section, as shown, but may also be of other shapes if desired.

In Figure 4, blocks 26 are illustrated which are each supported directly by'the grid members 27, here shown as of'circular cross section. These blocks are illustrated as being supported directly by the grid, i. e., without the interposition of fillers 24, but'it will be obvious that such an arrangement of fillers may be utilized by widening the grid receiving recesses of the blocks. If the grid serves as a heater as well as a support for the arch, it may be covered,

over with any suitable insulating covering 28.

The operation of the device is extremely simple. In building a furnace, the arch blocks may be placed in position and supported by false work and the grid lowered into position and keyed to the blocks by the members 24;, or the grid may be first positioned and the arch built up from below, th blocks 20 being first inserted and the construction finishing up with one of the blocks 21, which is moved upwardly and keyed into place.

When repairs are necessary owing to the burning out or fracturing, one of the damaged blocks 21 is unkeyed and lowered or broken out. This releases the flanking blocks 22. Fresh blocks 22 are supported in place and a fresh block 21 forced up between them and keyed to the grid. It will thus be seen that a repair may be executed without disturbance of more blocks than are actually destroyed or at most without the disturbance of more than the destroyed blocks plus two of the small blocks 22.

The blocks, when heated in the operation of the furnace, transfer a portion of their heat to the supporting means by contact and by radiation. The supporting means of the arch becomes quite hot and has a tendency to sag and let the arch down, so that the seams are opened on the lower side, permitting the blocks to burn very rapidly and producing a leaky arch. To.

overcome this sagging, it has been necessary to make these arch supports of very heavy material, taking up a great amount of space.

The rates of expansion and contraction of the blocks and of the metal support are quite different so that destructive stresses are set up in the structure. According to this invention, the arch supporting grid may be uite small. Valuable space is not encum ered with it and the amount of material required and the cost of maintenance is much less than for similar uncooled structures. The support remains at a practically contraction need be considered and allowed for. The cool support tends to keep the arch itself cool and therefore by avoiding extreme temperatures to prolong the life of the arch. Being cooled, the supporting grid does not change shape, Work or sag, and will therefore last indefinitely, whereas uncooled supports require frequent renewal or repair. The employment of a cooled supporting means enables detachable block arches, such as illustrated, to be used satisfactorily in furnaces in which they could not heretofore be used on account of the extreme heating of the support. I

\Vhile elliptical and circular tubes and certain specific forms of arch blocks have been shown, it will be understood that the invention is not limited to these particular details but may be altered in these respects 'as required without departing from the spirit of the invention.

Having thus described my invention, what I claim is f 1. The combination with an arch, a grid having longitudinal and transverse members located in different planes and of tubular formation for the passage of a cooling agent, the members in the lower plane being suspended from the members in the upper plane and the blocks of the arch being formed for supporting engagement with the grid members in oneplane.

2. In a device of the class described, a plurality of tubular members, a second plurality of tubular members arranged-at an angle to and below the first members, and tubular connections between said members where they cross one another, the members in one plane having cooling agent 'inletsand the members in the other plane having cooling agent outlets, and arch blocks suspended from the members in the lower plane.

3. In a device of the class described, a plurality of tubular supports adapted for the 110 passage of a cooling agent therethrough arranged substantially in parallelism, an arch composed of blocks arranged in a row extending transversely of said supports,'alternate blocks of said arch projecting upwardly 115 between the supports and being undercut in said upwardly projecting portions, and keys inserted between the undercut portions and the supports serving to hold the blocks to said supports'and to conduct heat'from the blocks to the supports.

4. In combination with a device according to claim 3, a plurality of tubular members adapted for the circulation of a cooling agent located above and transversely of the supports, and connections between said members and the supports wherethey cross adapted for the flow of a cooling agent from one to the'other.

5. In combination with a device accord- 1:50

ing to claim 3, a plurality of tubular members adapted for the circulation of a cooling agent located above and transversely of the supports, connections between said members and the supports where they cross adapted for the flow of a cooling agent from one to the other, furnace walls supporting said tubular members, and an insulating covering over said tubular members and block supports.

6. A device according to claim 3, in which adjacent faces of said alternate blocks slope toward one another at the bottom of the arch and support the intermediate blocks, said intermediate blocks terminating at the lower surface of the alternate blocks.

7 A furnace arch comprising a" series of supports, a series of refractory blocks undercut in the upper portions of their side surfaces, said undercut portions being adapted for insertion from beneath into position between adjacent supports, and keys between the supports and undercut portions of the blocks holding the blocks to the supports.

8. In a device of the character described, a grid comprising a plurality of tubular members, a second plurality of tubular mem-' bers arranged at an angle to and below the first members, and tubular connections be tween said members where they cross one another, said grid being provided with suitable inlet and outlet openings permitting circulation of a cooling agent through the tubular members thereof, and arch blocks suspended from the members in the lower plane.

In witness whereof, I have hereunto set my hand.

JOHN W. GATES. 

